Entecavir, [1S-(1α, 3α, 4β)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one, is currently being evaluated as a drug for use in treating hepatitis B viral infections.
Entecavir and its use as an antiviral agent are described in U.S. Pat. No. 5,206,244 to Zahler et al., assigned to the present assignee. Improved processes of preparing entecavir are described by Bisacchi et al., in WO 98/09964, also to the present assignee.
Colonno, et al. in WO 01/64221 describe compositions containing a low dose of entecavir administered on a daily basis to treat hepatitis B virus infection and/or co-infections.